Vehicle suspension

ABSTRACT

The vehicle suspension provides an axle assembly which may be mounted either on a truck-tractor or a truck-trailer. The suspension includes an axle which is suspended from the vehicle frame by means of a pair of elastomeric springs. A drawbar extends forwardly from the axle. The drawbar is connected, at its forward end, to structure depending from the vehicle frame. The connection includes resilient fastening means which permit some pivoting of the forward end of the drawbar about an axis transverse to the longitudinal axis of the drawbar and generally parallel to the axis of the axle. Lifting means are provided to raise the axle and associated wheels off the ground when desired. The vehicle suspension is adapted for use as a pusher type axle suspension for mounting on a truck forward of the drive axles thereof.

United States Patent [191 Granning VEHICLE SUSPENSION [75] Inventor: OleGranning, Detroit, Mich.

[73] Assignee: Granning Suspensions, Inc.,

' Dearborn, Mich.

[22] Filed: Dec. 20, 1971 [21] Appl. No.: 209,640

Related U.S. Application Data [62] Division of Ser. No. 45,613, June 12,1970, Pat. No.

3,481,623 12/1969 Campbell ..267I63R July 24, 1973 PrimaryExaminer-Philip Goodman Attorney-Edward A. Craig 5 7 ABSTRACT Thevehicle suspension provides an axle assembly which may be mounted eitheron a truck-tractor or a truck-trailer. The suspension includes an axlewhich is suspended from the vehicle frame by means of a pair ofelastomeric springs. A drawbar extends forwardly from the axle. Thedrawbar is connected, at its forward end, to structure depending fromthe vehicle frame. The connection includes resilient fastening meanswhich permit some pivoting of the forward end of the drawbar about anaxis transverse to the longitudinal axis of the drawbar and generallyparallel to the axis of the axle. Lifting means are provided to raisethe axle and associated wheels off the ground when desired. The vehiclesuspension is adapted for use as a pusher type axle suspension formounting on a truck forward of the drive axles thereof.

7 Claims, 4 Drawing Figures PATENIED M24!!! SHEEI 1 [1F 2 INVENTOR.

OLE GRANNING ATTORNEYS PAIENIEUJULZMQH 3, 747, 94

' sum 2 m 2 INVENTOR.

212 I66 OLE GRANNING ATTORNEYS VEHICLE SUSPENSION CROSS REFERENCE TORELATED APPLICATION This application is a division of application Ser.No. 45,613, filed June 12, 1970.

BACKGROUND OF THE INVENTION Law. If additional wheel are provided on atruck the permissible truck load is increased thus permitting thetrucker to haul a larger payload. In addition to comply ing with loadingregulations, it is also desirable to add an extra axle when the load isto be increased in order to prevent undue wear on the vehicle.

My present invention provides an axle assembly which may be mounted on atruck to provide the desired additional axle. I have provided asuspension system including an axle which may be used as a pusher typeaxle located forwardly of a driven axle. This axle incorporated certainnovel features in connection with the drawbar assembly and guide meanstherefor and in the axle configuration. A drawbar extends forwardly fromthe axle. I have provided a resilient fastening means for connecting theforward end of the drawbar to the vehicle frame which permits theforward end of the drawbar to pivot somewhat about an axis which istransverse to the longitudinal axis of the drawbar and generallyparallel to the axle axis. This arrangement prevents hunting and seekingof the axle under certain conditions. For example, when the axle is in alowered position as a result of a wheel being located in a depression onthe roadway, the resilient fastening means will be pivoted and will urgethe axle back to a level position. In prior constructions, the resilientconnection would tend to strongly urge the axle back to its levelposition even when it should remain downwardly. For example, when thebrakes are applied in prior devices, the axle tends to pop up when itshould not. The present connection minimizes this tendency.

Additionally, I have provided elastomeric springs for this suspension asopposed to pneumatic or metallic springs as have been used in the past.Other features of the invention include a novel lifting arrangement toleft the axle off the ground when there is no load on the vehicle thussaving tire wear and engine fuel.

SUMMARY OF THE INVENTION The suspension is adapted for a vehicle havinga frame. The suspension includes a suspension support structure separatefrom the vehicle frame. The suspension support structure is of a sizeand includes structure for mounting thereof on the vehicle frame. Anaxle is provided. A spring structure is securable to the vehicle frameand is connected to the axle for suspension of the axle. A drawbarextends outwardly from the axle towards the forward end of thesuspension. Resilient fastening means are pivotable about an axistransverse to the longitudinal axis of the drawbar and generallyparallel to the axis of the axle. Vertical drive means are provided. Thevertical drive means comprise downwardly depending means defining guidesurface structure for securement to the vehicle frame and verticallyslidable structure secured to the axle for sliding engagement with theguide surface structure.

In the drawings:

FIG. 1 is an elevational view of a truck illustratively having mountedthereon a pusher type axle vehicle suspension in accordance with oneembodiment of the present invention;

FIG. 2 is a side elevational view of the vehicle suspension of FIG. 1 inaccordance with one embodiment of the present invention;

FIG. 3 is a plan view of the vehicle suspension of FIG. 2; and a FIG.4'is a front elevational view of the vehicle suspension of FIG. 2.

The pusher type 'axle suspension arrangement 154 illustrated in FIGS.2-4 is adapted, as illustrated in FIG. 1, for mounting on a truck 156forward of the tandem drive axles 158, 160 illustrated. For this reason,the suspension 154 is designated as a pusher type. However, theprinciples of the suspension may also be applied to a trailing type axlevehicle suspension which is mounted behind the driven axle of a tractoror is mounted on the trailer which is pulled by the tractor.

Referring more specifically to the structure illustrated in FIGS. 2-4,an axle 162 is supported at its center by means of a longitudinallyextending drawbarguide structure 164. The center portion 166 of the axleis curved downwardly to provide room thereabove for extension thereoverof the drive shaft 168 (indicated in dotted lines) which must, ofcourse, be accommodated to permit transmission of power from the engineover the axle 162 into connection with the driven axle I58, 160.

The drawbar portion of the structure 164 is welded at 174, 175 to theaxle. As will be noted in FIG. 3, the drawbar portion includes inwardlyconverging legs 176, 178 which extend the points of attachment adjacentthe outer ends of the axle into connection with each other at a pointcentrally located with respect to the axle to thus define a V-shapedconfiguration when viewed in plan. A pair of forwardly and downwardlyV-shaped legs 180, 182 are bolted to the truck frame members 184, 186(indicated in dotted lines).

A cylindrical support member 188 extends between the lower ends of thelegs 180, 182. A coupling 190 extends from the juncture of the legs 176,178 into engagement with the cylindrical member 188 centrally thereof.The coupling 190 is a resilient coupling pivotable about an axistransverse to the longitudinal axis of the drawbar portion of thestructure 164 and generally parallel to the axis of the axle 162. Thecoupling may include an outer metallic sleeve coupling member on thedrawbar having a longitudinal axis as described with a resilientelastomeric ring within the metallic sleeve as described in theaforesaid application Ser. No. 45,613, filed June 12, 1970.

A pair of brackets 194, 196 are bolted to the truck frame rearwardly ofthe axle 162. The brackets 194, 196 have generally horizontallyextendingplates 198, 200 secured thereto. A pair of elastomeric springs202, 204 are connected at their upper end to the underside of the plates198, 200. The springs 202, 204 are generally oval in cross-section inthe unloaded condition as illustrated in FIGS. 2 and 4. When a load isapplied the springs deform laterally and assume a somewhat doughnutshape under full load conditions. These springs are desirable from thecost standpoint and result in a maintenance-free life. Auxiliary shockabsorbers are not necessary with this construction. The springs resultin built-in damping. The springs are fabricated from a rubber-likeelastomeric material.

A transversely extending cylindrical support element 206, also having adownwardly curved center portion, extends between and beyond the springs202, 204. A flat horizontal plate 208, 210 is secured to the element206, as by welding, beneath each of the springs 202, 204. The lowerportions of the springs are bolted to the plates 208, 210, the springsbeing provided with metallic plates embedded into each end thereof.

An upwardly extending anchor element 212, 214 is provided at each outerend of the transverse element 206. The anchor elements 212, 214 areU-shaped and receive the rearwardly extending portions 216, 218 of thedrawbar legs 176, 178. As will be noted in FIG. 2, a cylindrical locaterelement 222 is provided above each of the drawbar elements and isreceived in a curved recess. The element 222 is bolted in place. Anotherbolt 224 is provided beneath the end of the drawbar to thereby hold thedrawbar securely in place. The lower surfaces 225 of the portions 216,218 are curved to thereby permit limited pivoting. As will beappreciated, the structure described connects the drawbar to the springs202, 204 and thus the axle 162 and the springs to the truck frame tothereby provide a resilient suspension for the entire assembly.

The guide portion 226, 228 extends upwardly from the drawbar legs 176,178. A wear plate 230, 232 is bolted to the sides of the truck frameelement in general alignment with the upper end of each of the portions226, 228. A threaded opening is provided on the upper end of each of theportions 226, 228 to receive the threaded shank 234, 236 of a wear bolthaving an enlarged head 238, 240. The wear bolts are in sliding contactwith the plates 230, 232 and describe an arc, upon upward and downwardmovement of the axle 162, which extends from the lower right hand cornerof the wear plates, as viewed in FIG. 2, towards the upper left corner.Both the wear plates and the wear bolts are fabricated of a hardenedmetal for long life. This structure serves to guide the axle suspensionin its up and down movement during use without any pivoting of the guidestructure about an axis parallel to the longitudinal axis of the drawbarportion of the structure 164. As either the wear plate or wear bolt iseroded as a result of the sliding contact, the wear bolts may beadjusted inwardly by threading the shanks towards the wear plates.Adjustment may also be made to accommodate differences in vehicle framesizes.

An air lift structure 192 is provided between the truck frame and asupport platform 193 to permit pneumatic lifting of the axle assemblywhen it is desired to lift the wheels off the ground. It is desirable tolift the axle upwardly to disengage the wheels from the surface of theroadway when the vehicle is not loaded in order to reduce drag caused byengagement of the wheels and to reduce wear on the tires. The liftingstructure comprises a cup-shaped member 195 positioned above the axle162. A pneumatic bellows 197 is provided within the member 195. Theupper portion of the bellows 197 is against the member 195 while thelower portion of the bellows is supported by a support platform 193(FIG. 3) which extends between the vehicle frame and members 186, 184and is secured thereto. A cable 199, 201 is attached to diametricallyopposite edge portions of the member 195. The cables extend throughguide structures and are attached at the lower ends thereof to brackets203 secured to the structure 164. When it is desired to raise the axle162, air under pressure is injected into the bellows 197 causing thebellows to expand and lift the member upwardly. The cables 199, 201 thenraise the axle 162 against the action of springs 202, 204 causing theaxle to be raised a suffrcient distance to raise the wheels off theground. The bellows 197 is exhausted when it is desired to lower theaxle.

What I claim as my invention is:

1. In a suspension for a vehicle having a frame, comprising a suspensionsupport structure separate from the vehicle frame, said suspensionsupport structure being of a size and including structure for mountingthereof on the vehicle frame, an axle, a spring structure securablebetween the vehicle frame and said axle to resiliently support saidaxle, a drawbar extending outwardly from the axle towards the forwardend of said suspension support structure, resilient fastening meanspivotable about an axis transverse to the longitudinal axis of thedrawbar and generally parallel to the axis of the axle securing thedrawbar to the suspension support structure, and vertical guide meanscomprising downwardly depending means defining guide surface structurefor securement to the vehicle frame and vertically slidable structuresecured to the axle for sliding engagement with the guide surfacestructure, the combination of said vertically slidable structure andguide surface structure substantially preventing pivoting of the drawbarabout its longitudinal axis.

2. A suspension as defined in claim 1, further characterized in thatsaid suspension is adapted to be mounted forwardly of a drive axle, saidsuspension axle having a downwardly curved center portion to permitpassage thereover of the vehicle drive shaft.

3. A suspension as defined in claim 2, further characterized in thatsaid drawbar includes a pair of legs each secured at one end to thesuspension axle adjacent an outer end of the suspension axle, said legsconverging forwardly of the suspension axle to form a single couplingstructure for securement to the resilient fastening means.

4. A suspension as defined in claim 3, further characterized in thateach of said legs has a portion extending rearwardly from the suspensionaxle, said suspension support structure including a depending axlesupport structure at the rearward end of the suspension, said rearwardlyextending portions of the drawbar legs being pivotally attached to saiddepending axle support structure.

5. A suspension as defined in claim 3, further characterized in thatsaid vertically slidable structure secured to the suspension axlecomprises a pair of upstanding elements secured to the rearward portionof the drawbar legs, wear plates securable to the vehicle frame inalignment with said upstanding elements and defining the guide surfacestructure, and guide elements on the upper portion of said upstandingelements for sliding engagement with the wear plates.

6. A suspension as defined in claim 5, further characterized in thatsaid guide elements include means for adjustment thereof with respect tothe wear plates.

3,747,948 6 7. A suspension as defined in claim 1, further characblesextending from said inflatable lift element into terized in theprovision of a pneumatic lifting assembly connection with the axle tolift the axle upon inflation for said axle comprising an inflatable liftelement securof the inflatable element. able to the vehicle frame and apair of spaced apart ca-

1. In a suspension for a vehicle having a frame, comprising a suspensionsupport structure separate from the vehicle frame, said suspensionsupport structure being of a size and including structure for mountingthereof on the vehicle frame, an axle, a spring structure securablebetween the vehicle frame and said axle to resiliently support saidaxle, a drawbar extending outwardly from the axle towards the forwardend of said suspension support structure, resilient fastening meanspivotable about an axis transverse to the longitudinal axis of thedrawbar and generally parallel to the axis of the axle securing thedrawbar to the suspension support structure, and vertical guide meanscomprising downwardly depending means defining guide surface structurefor securement to the vehicle frame and vertically slidable structuresecured to the axle for sliding engagement with the guide surfacestructure, the combination of said vertically slidable structure andguide surface structure substantially preventing pivoting of the drawbarabout its longitudinal axis.
 2. A suspension as defined in claim 1,further characterized in that said suspension is adapted to be mountedforwardly of a drive axle, said suspension axle having a downwardlycurved center portion to permit passage thereover of the vehicle driveshaft.
 3. A suspension as defined in claim 2, further characterized inthat said drawbar includes a pair of legs each secured at one end to thesuspension axle adjacent an outer end of the suspension axle, said legsconverging forwardly of the suspension axle to form a single couplingstructure for securement to the resilient fastening means.
 4. Asuspension as defined in claim 3, further characterized in that each ofsaid legs has a portion extending rearwardly from the suspension axle,said suspension support structure including a depending axle supportstructure at the rearward end of the suspension, said rearwardlyextending portions of the drawbar legs being pivotally attached to saiddepending axle support structure.
 5. A suspension as defined in claim 3,further characterized in that said vertically slidable structure securedto the suspension axle comprises a pair of upstanding elements securedto the rearward portion of the drawbar legs, wear plates securable tothe vehicle frame in alignment with said upstanding elements anddefining the guide surface structure, and guide elements on the upperportion of said upstanding elements for sliding engagement with the wearplates.
 6. A suspension as defined in claim 5, further characterized inthat said guide elements include means for adjustment thereof withrespect to the wear plates.
 7. A suspension as defined in claim 1,further characterized in the provision of a pneumatic lifting assemblyfor said axle comprising an inflatable lift element securable to thevehicle frame and a pair of spaced apart cables extending from saidinflatable lift element into connection with the axle to lift the axleupon inflation of the inflatable element.